defense lies only in its capacity for rapid displacement and the swiftness of its evolutions.  Its rear is badly exposed:  its field of visibility is very limited at the sides, and objects can be seen only above and below,—­below, minus the dead angle of the motor and the cock-pit.  The pilot can easily lose sight of the airplanes in his own group or that of the enemy, so that if he is alone, he is in danger of being surprised.  On the other hand, one condition of his own victory is to surprise the enemy, especially if he attacks a two-seated machine whose range of fire is much broader, or if he does not hesitate to choose his victim from among a group.  The Spad pilot makes use of the sun, of fog, of clouds.  He flies high in order to hold the advantage of being able to pounce down upon his enemy while the enemy approaches prudently, timidly, suspecting no danger.

The battle of the Somme was the most favorable for solitary airplanes, or airplanes coupled like hunting-dogs.  Since then methods have changed, and the future belongs to fighting escadrilles or groups of machines.  But at that time the one-seated airplane was king of the air.  One of them was enough to intimidate enemy airplanes engaged in regulating artillery fire and in short-distance scouting, making them hesitate to leave their lines, and to frighten barrier patrols of two or even four two-seated airplanes, in spite of their shooting superiority, into turning back and disbanding.  The one-seated enemy machines never ventured out except in groups, and even with the advantage of two against one refused to fight.  So the one-seated French machine was obliged to fly alone, for if it was accompanied by patrols, the enemy fled and there was no one to attack; whereas, when free to maneuver at will, the solitary pilot could plan ruses, hide himself in the light or in the clouds, take advantage of the enemy’s blind sides, and carry out sudden destructive attacks which are impossible for groups.  Our airmen never speak of the Somme without a smile of satisfaction:  they have retained heroic memories of that campaign.  Afterwards, the Germans drilled their one-seated or two-seated patrols, trained them in resistance to isolated attacks, and taught them in turn how to attack the solitary machine which had ventured out beyond its own lines.  We were obliged to alter our tactics and adopt group formation.  But the strongest types of our enemy-chasing pilots were revealed or developed during the battle of the Somme.

Moreover, our aviators at that time were incomparable; and in citing the most illustrious among them one risks injustice to their companions whose opportunities were less fortunate and whose exploits were less brilliant but not less useful.  The cavalry, artillery, and infantry were drawn upon for recruits for the aviation branch of the army, and it appeared a difficult undertaking to fuse such different elements; but as all shared the same life and the same dangers, had similar tastes,